"Had it [Eat Streat] not been open nobody would even have known about it."
He said every building project brought its own surprises, regardless of what experts had been consulted.
The unexpected twisting of the timber was "one of the more obvious" of those.
"Things happen that you don't expect sometimes," he said. "We tell clients to have a contingency to cover stuff like this."
Mr Willard said a solution was being discussed with the timber engineers, which involved treating the wood differently.
Those planks that could be fixed would be while others might need to be replaced.
Describing the issue as a "nuisance", Mr Willard said the East Streat design had been unique, as the timber walkway had to be able to carry fire engines - not just pedestrians.
"No one's ever done that before in Australasia."
Rotorua District Council inner city enterprises manager Nick Dallimore said the council was waiting for the final design solution for the boardwalk.
In the meantime daily checks and maintenance were continuing to ensure the safety of the area.
"I don't think it's the end of the world, it's just something that needs to be sorted and that's fine," he said.
Mr Dallimore said it was too early to say who would cover the cost of fixing the boardwalk but the council had absolutely no regrets about opening the street before it was fully finished.
"At the end of the day the project was [opened] later in the year than we would have hoped," he said.
"Opening for Christmas was important to get it back into the public space. The only significant design issue was the boardwalk."
Planned construction work is continuing on the roof, beams, lighting and wooden fencing between restaurants, he said.
Mr Dallimore said he was hopeful the street would be completed by the end of this month as planned, despite the boardwalk issues.
"I don't want it to go on forever," he said, adding it was vital the work was done properly so it would last.